Opacity color

.opacity30 {
  opacity: 0.3;
  filter: alpha(opacity=30); /* For IE8 and earlier */
}

Css opacity background color

background: rgba(255, 255, 255, 0.25);

Background color with opacity

h1 {background-color:rgba(255,0,0,0.3);}

Background color opacity

rgba(51, 170, 51, .1)    /*  10% opaque green */ 
rgba(51, 170, 51, .4)    /*  40% opaque green */ 
rgba(51, 170, 51, .7)    /*  70% opaque green */ 
rgba(51, 170, 51,  1)    /* full opaque green */

Source: stackoverflow.com

Similar codes

0 vote123 views1 answer
Estilos de scroll css
CSS
0 vote138 views2 answers
Print to pdf setting css for A4 size
CSS
0 vote116 views1 answer
To make card box appear more bigger when hover
CSS
0 vote112 views1 answer
How to make an element vertically centered in a dv
CSS
0 vote126 views1 answer
Css efeito negativo fotos
CSS
0 vote110 views1 answer
Avatar change design html css
CSS
0 vote119 views1 answer
Horizontal rule plus text
CSS
72 votes135 views6 answers
Css font size
CSS
2 votes145 views5 answers
How to reset postgres password
CSS
6 votes127 views2 answers
How to add scss to a react app
CSS